TW201506985A - Plasma treatment device and sealing method therefor - Google Patents

Abstract

Provided is a plasma treatment device in which the properties of a film formed by plasma treatment can be improved. This invention has: a treatment chamber (10) for defining a sealed space (11); a plasma-forming electrode (36) provided in the sealed space; an interior conductor (21) extending from the exterior of the treatment chamber (10) toward the plasma-forming electrode (36) through an opening (13h) formed in the treatment chamber (10); exterior conductors (22, 13) surrounding the periphery of the interior conductor (21), and defining the opening (13h) and a void (23) bounded on one side by the interior conductor (21); a sealing member (60) for dividing the void (23) into an atmosphere-side space and a space communicating with the sealed space (11), the sealing member (60) being formed from an insulator and being connected to the interior conductor (21) and the exterior conductors (22, 13); and an anti-discharge insulator (100) for filling a portion of the void (23) corresponding to the space formed on the sealed-space (11) side relative to the sealing member (60).

Description

Plasma processing device and sealing method thereof

The present invention relates to a plasma processing apparatus and a sealing method thereof for applying a plasma treatment to a substrate.

In the manufacturing process of a flat panel display, a solar cell, a semiconductor device, etc., a plasma processing apparatus is used for formation, etching, etc. of a film. The inventors of the present invention proposed a device disclosed in Patent Document 1 or the like as a plasma processing apparatus.

Here, FIG. 7 is a cross-sectional view showing a schematic view of a plasma processing apparatus of the same type as that of Patent Document 1. The apparatus is provided with a metal processing chamber 10 that partitions the sealed space 11 and a holder 14 that is disposed in the processing chamber 10 for mounting the substrate 16, and is formed at an upper portion of the processing chamber 10. The cover 13 is connected to the coaxial tube 20, and the dielectric plate 34 disposed under the cover 13 above the holder 14, and the electrode 36 disposed on the surface of the dielectric plate 34. . The inner conductor 21 of the coaxial tube 20 extends through the opening 13h of the cover 13 to the upper surface of the dielectric plate 34, and the flange of the lower end portion of the cylindrical outer conductor 22 is surrounded by the opening 13h of the cover 13. Make a connection. The electrode 36 is provided so as to cover most of the lower surface of the dielectric plate 34 so that the outer peripheral portion 34p of the dielectric plate 34 is exposed to the sealed space 11. The gap 23 between the inner conductor 21 of the coaxial tube 20 and the outer conductor 22 is connected to the atmosphere. Therefore, in order to seal the sealed space 11, an O-ring 40 having heat resistance is provided between the lower surface of the lid body 13 and the dielectric plate 34. At the O-ring 40, a synthetic rubber excellent in heat resistance and plasma resistance is used, and for example, a perfluoroelastomer is used. In this device, the microwave introduced into the inner conductor 21 from a microwave supply source (not shown) propagates through the coaxial tube 20, passes through the dielectric plate 34, and passes from the periphery of the dielectric plate 34. The portion 34p propagates along the surface 36f of the electrode 36 as the conductor surface wave TM. The plasma is excited by the microwave as the conductor surface wave TM propagating on the surface 36f of the electrode 36.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4944198

In the above-described plasma processing apparatus, the O-ring 40 formed of a heat-resistant elastomer is used to seal the closed space 11. However, the O-ring 40 is configured in micro as it is as described above. The path through which the wave passes is therefore heated to 200 ° C in the plasma treatment. Further, it is known that when the O-ring 40 is heated, it is exposed to oxygen radicals or hydrogen radicals formed by the excited plasma and initiates a chemical reaction, gasification. The substance system will leak into the confined space 11. The gasified substance leaking into the sealed space 11 of the processing chamber 10 is introduced into the film on the substrate 16 formed by the plasma treatment in the processing chamber 10, and there is a property of the film. The problem of impact.

The present invention provides a plasma processing apparatus capable of improving the characteristics of a film formed by plasma treatment and a sealing method applied to the plasma processing apparatus.

A plasma processing apparatus according to the present invention is characterized by comprising: a processing chamber for dividing a sealed space; and a plasma forming electrode provided in the sealed space; and an internal conductor from the processing chamber The outer portion is extended toward the plasma forming electrode by an opening formed at the processing chamber; and the outer conductor surrounds the periphery of the inner conductor, and is partitioned between the outer conductor and the inner conductor a gap, and defining the opening; and a sealing member connected to the inner conductor and the outer conductor, and configured to partition the gap into a space on the atmosphere side and a space in communication with the sealed space, and the insulator And a discharge preventing member that fills a space formed in the sealed space side with respect to the sealing member in the gap, and is Formed by an insulator.

The sealing method of the present invention is a sealing method of a plasma processing apparatus, the plasma processing apparatus comprising: a processing chamber for dividing a sealed space; and an electrode for forming a plasma, which is disposed in the sealed space And an inner conductor extending from the outside of the processing chamber through an opening formed at the processing chamber toward the electrode for forming the plasma; and an outer conductor surrounding the inner conductor A gap is defined between the outer conductor and the inner conductor, and the opening is defined, and the plasma processing apparatus is sealed by a sealing member formed by an insulator, and the inner conductor and the outer conductor. The space is partitioned into a space on the atmosphere side and a space in contact with the sealed space, and a space formed in the sealed space with respect to the sealing member in the space is formed by an insulator Landfill.

According to the present invention, since the O-ring of the elastic system is not used in the sealing in the vicinity of the plasma forming region of the processing chamber, the gasification substance is not generated, and the plasma treatment can be performed. The properties of the film formed on the substrate are improved. Further, according to the present invention, by filling the space formed on the side of the sealed space with respect to the sealing member by the discharge preventing member, it is possible to prevent the inner conductor and the outer portion from being decompressed when the space is decompressed. When a discharge occurs between the conductors, as a result, it is possible to stably excite a high-density plasma.

1, 1A‧‧‧ plasma processing equipment

10‧‧‧Processing chamber

13‧‧‧ cover (external conductor)

13h‧‧‧ openings

14‧‧‧Support

20, 20A‧‧‧ coaxial tube

21‧‧‧Internal conductor

22‧‧‧External conductor

34‧‧‧Dielectric plate

36‧‧‧Electrode

60‧‧‧ Sealing members

70, 71‧‧‧ Sealing metal

100‧‧‧Discharge prevention member

150‧‧‧Electrical elastic members

200‧‧‧Multi-leaf fan

Fig. 1 is a cross-sectional view showing the outline of a plasma processing apparatus according to an embodiment of the present invention.

Fig. 2 is a plan view as seen from the lower side of the electrode of Fig. 1.

Fig. 3 is a cross-sectional view showing the outline of a plasma processing apparatus according to an embodiment of the present invention.

[Fig. 4] An enlarged cross-sectional view of an important part of Fig. 3.

Fig. 5 is a perspective view of a conductive elastic member.

Fig. 6 is a cross-sectional view taken along line VI-VI of Fig. 3;

Fig. 7 is a cross-sectional view showing a schematic view of a plasma processing apparatus using an elastic O-ring at the periphery of a region where plasma is formed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, constituent elements that have substantially the same functional configurations are denoted by the same reference numerals, and the description thereof will not be repeated.

First embodiment

The plasma processing apparatus 1 (hereinafter referred to as the apparatus 1) shown in FIG. 1 and FIG. 2 is used, for example, in various plasma processing such as plasma CVD (Chemical Vapor Deposition). This apparatus 1 has the same basic construction as the plasma processing apparatus illustrated in FIG. that is That is, the device 1 is the same as that described in FIG. 7, and is provided with a processing chamber 10, a holder 14, and a coaxial tube 20, a dielectric plate 34, and an electrode 36. In addition to the above-described configuration, the sealing member 60, the sealing metals 70 and 71, and the discharge preventing member 100 are provided in the present embodiment. However, there is no difference between the dielectric plate 34 and the upper cover 13. Sealed O-ring 40.

The processing chamber 10 is formed of a conductive material such as aluminum alloy or stainless steel and is connected to a reference potential. At the bottom of the processing chamber 10, an exhaust port 20 for exhausting the atmosphere in the processing chamber 10 is provided, and at the exhaust port 20, an unillustrated portion disposed outside the processing chamber 10 is connected Exhaust device such as vacuum pump. With this exhaust device, the sealed space 11 is decompressed. Between the outer peripheral edge portion of the lower surface of the upper cover 13 and the upper end portion of the processing chamber 10, an elastic O-ring 50 is provided to seal the upper cover 13 and the processing chamber 10. Since the O-ring 50 is sufficiently separated from the plasma formation region, there is no possibility of chemical reaction with oxygen radicals or hydrogen radicals formed by the plasma.

The dielectric plate 34 is formed of a material such as alumina and is disposed under the upper cover 13. The plasma forming electrode 36 is formed of a material such as aluminum alloy and is disposed under the dielectric plate 34. Further, the plasma forming electrode 36 is not shown, but is fixed to the upper cover 13 together with the dielectric plate 34 by a locking member such as a screw. The dielectric plate 34 and the plasma forming electrode 36 are generally formed in a square shape as shown in FIG. 2, and the dielectric plate 34 is provided. The electrode 36 is formed to be larger than the electrode for forming the plasma, and only the outer peripheral edge portion 34p of the dielectric plate 34 is exposed to the sealed space 11.

The processing chamber 10 also includes an upper cover 13 and is formed of a conductive material such as aluminum alloy and is grounded. The processing chamber 10 is lined with a confined space 11 that can be decompressed. The holder 14 is formed, for example, of aluminum nitride, and has a power supply portion (not shown) for electrostatically adsorbing the substrate 16 and applying a predetermined bias voltage, and heating the substrate 16 to A heater (not shown) of a predetermined temperature.

The coaxial tube 20 includes a round bar-shaped inner conductor 21 extending toward the electrode 36, and a cylindrical outer conductor 22 surrounding the inner conductor 21, and is disposed outside the processing chamber 10. The microwave supply source (not shown) is connected to receive the supply of microwave power. The inner conductor 21 and the outer conductor 22 are formed of a low-resistance material such as oxygen-free copper. The inner conductor 21 extends through the opening 13h of the cover 13 to the upper surface of the dielectric plate 34, and the lower end surface of the inner conductor 21 is adjacent to the upper surface of the dielectric plate 34. Preferably, a narrow gap of about 0.2 to 0.4 mm is provided between the inner conductor 21 and the dielectric plate 34 at normal temperature. The reason for this is that the lower end surface of the inner conductor 21 is moved downward toward the lower end of the inner conductor 21 even if it is caused by thermal expansion of the inner conductor 21, or there is a variation in the processing size of the inner conductor 21, and the inner conductor 21 is not caused. The dielectric plate 34 is pressed down and causes the dielectric plate 34 to be broken. The flange at the lower end portion of the outer conductor 22 is connected to the periphery of the opening 13h of the lid body 13. Flange at the lower end of the outer conductor 22 The system is fixed to the cover 13 and the two are electrically connected. The opening 13h formed at the lid body 13 has an inner diameter which is formed to be slightly the same as the inner diameter of the outer conductor 22, and a gap 23 is formed between the inner conductor 21 and the outer conductor 22 and the opening 13h. . That is, the opening 13h of the cover 13 is a portion of the gap 23 and forms part of the outer conductor of the present invention. The void 23 is in communication with the atmosphere.

The sealing member 60 is formed in a ring shape and disposed at a gap 23 between the inner conductor 21 and the outer conductor 22, and partitions the gap 23 into a space on the atmosphere side and a space in communication with the sealed space 11. The sealing member 60 is formed of an insulator such as alumina. The inner peripheral portion of the upper end of the sealing member 60 and the outer surface of the inner conductor 21 are sealed by the sealing metal 70, and the outer peripheral portion of the lower end of the sealing member 60 and the inner wall surface of the opening 13f are The sealing metal 71 is sealed. At the sealing metals 70, 71, a metal having a low coefficient of thermal expansion is used. For example, there is a Kovar alloy in which nickel and cobalt are blended in iron, or a nickel-based alloy (trade name: INCONEL) containing nickel, chromium, niobium, molybdenum or the like based on nickel. The sealing metal 70 is welded to the inner conductor 21 and the sealing member 60, respectively, and the sealing metal 71 is welded to the sealing member 60 and welded to the inner wall surface of the opening 13f. The seal metals 70 and 71 are formed in a cylindrical shape in order to secure the size of the inner conductor 21 in the central axis direction to some extent. The reason for this is that since the members connected to the sealing metals 70, 71 are deformed by thermal expansion, stress is applied to the sealing metals 70, 71, but by the dimension of the central axis. Some kind The degree of assurance is that the stress can be received by its elasticity and the sealing metal 70, 71 is prevented from being destroyed.

The discharge preventing member 100 is formed in a ring shape, and the diameter of the through hole 100a formed at the center portion is formed such that the inner conductor 70 is fitted, and the outer peripheral surface 100b of the upper end side is fitted. The inner circumferential surface of the annular sealing metal 70 is formed, and the outer peripheral surface 100c of the lower end side is formed so as to be fitted to the inner wall surface of the opening 13h of the upper cover 13. Further, the height of the discharge preventing member 100 (the dimension of the inner conductor 70 in the central axis direction) is a size slightly the same as the distance between the lower surface of the sealing member 60 and the upper surface of the dielectric plate 34. In this manner, the discharge preventing member 100 is formed by the space SP which is a portion of the gap 23 which is defined by the sealing member 60 and the sealing metal 71, the inner wall surface of the opening 13h, and the upper surface of the dielectric plate 34. The size of the landfill is formed. The discharge preventing member 100 is preferably formed of an insulator, and is preferably a material having a low absorption property using microwaves. For example, quartz, alumina, or a fluorinated carbon resin (trade name: TEFLON (registered trademark)) or the like can be used as a material for forming the discharge preventing member 100.

Here, the action of the discharge preventing member 100 will be described. The space SP described above is sealed by the sealing member 60 and the sealing metals 70 and 71 with respect to the air gap 23 on the atmosphere side, and is connected to the sealed space 11 of the processing chamber 10. In the processing chamber 10, if the plasma treatment is performed, the sealed space 11 is decompressed, and the space SP is also decompressed. In this state, the coaxial tube 20 is supplied. When a strong microwave is given, the microwave propagates through the dielectric plate 34 at the coaxial tube 20, and then acts as a conductor surface wave TM from the outer peripheral portion 34p of the dielectric plate 34 along the surface 36f of the electrode 36. propagation. The plasma is excited by the microwave as the conductor surface wave TM propagating on the surface 36f of the electrode 36. At this time, since the space SP is a passage path of microwaves, abnormal discharge is likely to occur in the space SP. When the abnormal discharge occurs, the microwave power is consumed, so that the plasma cannot be normally excited on the surface of the plasma forming electrode 36. Further, the member existing in the vicinity of the region where the abnormal discharge occurs may be heated and broken. Therefore, in the present embodiment, the space SP is filled by providing the discharge preventing member 100 in the space SP, and the occurrence of abnormal discharge is surely prevented. That is, in order to seal the opening 13h of the processing chamber 10, instead of the O-ring 40 of the prior art, if the sealing member 60 and the sealing metal 70, 71 are used, it is inevitably formed in the microwave path. There is a space SP of a certain size. However, by filling the space SP with the discharge preventing member 100, the plasma can be stabilized and the damage of the device due to abnormal discharge can be prevented. . Further, since the elastic O-ring 40 is not used, the characteristics of the film formed by the plasma treatment can be improved.

Second embodiment

Next, a plasma processing apparatus according to another embodiment of the present invention will be described with reference to Figs. 3 to 6 . In addition, in Figures 3 to 6, The same components are denoted by the same components in the first embodiment. In the present embodiment, other aspects of the discharge preventing member and other forms of the coaxial tube will be described.

As in the above, by the gap 23 to be sealed The space SP formed above the plasma forming electrode 36 is filled by the discharge preventing member, and abnormal discharge can be prevented. However, if the space SP is a complicated shape or is deformed, there is a case where it is difficult to fill the space SP by the insulator formed integrally. Therefore, the plasma processing apparatus 1A (hereinafter referred to as the apparatus 1A) of the present embodiment is a discharge preventing member, and the first discharge prevention is formed in addition to the shape of the space in which the abnormal discharge occurs in the above-described manner. In addition to the member 100A, the second discharge preventing member 100B formed to have fluidity is also provided. In FIGS. 3 and 4, the sealing member 60A is connected to the inner conductor 21A by the sealing metal 70A, and is connected to the outer peripheral edge portion of the opening 13h of the upper cover 13 by the sealing metal 71A. The gap 23 is partitioned into the atmosphere side and the electrode 36 side by the sealing member 60A and the sealing metals 70A and 71A, and a space that communicates with the sealed space 11 is formed on the electrode 36 side. The space SP3 formed between the lower end surface of the sealing member 60A and the upper surface of the dielectric plate 34 is the first dielectric material formed into a ring shape in conformity with the space SP3. The discharge preventing member 100A is filled. The second discharge member 100B is housed in a space SP1 formed between the inner conductor 21A and the inner circumferential surface of the sealing member 60A, and the sealing member 60A, the sealing metal 71A, the upper cover 13, and the first discharge prevention structure. In the space SP2 surrounded by the piece 100A.

The second discharge member 100B is a plurality of small granular bodies (for example, spherical balls having a diameter of about 1 mm) formed of alumina, a fluorinated carbon resin (trade name: TEFLON (registered trademark)), quartz, or the like. It has fluidity. Therefore, it is possible to fill the space in accordance with the shape of the space to be accommodated, and it is not necessary to perform the processing so as to conform to the shape of the space in which the insulator is housed. The second discharge member 100B is not limited to the granular body, but may be a powder or a liquid. In the case of a liquid, the space can also be filled by a dielectric liquid having a small dielectric loss in the microwave band, for example, by a fluorine-based liquid (trade name: fluorinert, galden, etc.).

Next, the configuration of the coaxial tube will be described. In the first embodiment, a slight gap is formed between the lower end surface of the inner conductor 21 and the upper surface of the dielectric plate 34. When the size of the gap is changed by the temperature change of the inner conductor 21, the load impedance from the side of the coaxial tube 20 to the electrode 36 is largely changed, and the control of the electric power supplied by the plasma becomes difficult. Further, if a gap is formed between the inner conductor and the dielectric plate, abnormal discharge may occur.

In order to solve the above problem, the device 1A of the present embodiment is provided with a movable conductor plate 21B between the lower end surface of the inner conductor 21A constituting the coaxial tube 20A and the upper surface of the dielectric plate 34, and is disposed inside the movable conductor plate 21B and the inside. A conductive elastic member 150 is disposed between the lower end faces of the conductors 21A. Further, at the outer peripheral surface of the cylindrical outer conductor 22 constituting the coaxial tube 20A, it is installed to air-cool the inner conductor 21A. But the sirocco fan is 200.

The movable conductor plate 21B is formed in a disk shape having a diameter slightly the same as that of the inner conductor 21A, and is formed with a groove 21Bt for receiving the annular shape of the conductive elastic member 150 on the upper surface. The movable conductor plate 21B is the same as the inner conductor 21A, and is formed of a low-resistance material such as copper. As shown in FIG. 4, a gap Gp is formed between the lower end surface of the inner conductor 21A and the upper surface of the movable conductor plate 21B due to the insertion of the conductive elastic member 150.

The conductive elastic member 150 is a spring which is formed into a ring shape by winding a wire wound in a spiral shape as shown in FIG. The conductive elastic member 150 is formed of a metal such as stainless steel or phosphor bronze, and has electrical conductivity. The inner conductor 21A and the movable conductor plate 21B are constantly electrically connected by the presence of the conductive elastic member 150. In addition to the wire material, the conductive elastic member 150 may be formed by winding a strip-shaped spring material into a spiral shape and forming a ring shape, and processing the flat spring material as a leaf spring. Some of the springs are coated with nickel, gold, silver, etc. Further, it is also possible to apply a metal plating to an O-ring made of resin.

In the conductive elastic member 150, the movable conductor plate 21B is pressed with a moderate elastic force, and the movable conductor plate 21B is adhered to the dielectric plate 34. Even if the inner conductor 21A is moved downward toward the lower side due to thermal expansion of the inner conductor 21A, or there is a variation in the processing size, it is possible to absorb deformation or unevenness by elastic deformation and prevent the movable conductor plate from being displaced. An empty space between 21B and dielectric plate 34 Gap.

As shown in FIG. 5, in the wall surface of the outer conductor 22A to which the exhaust port 201 of the multi-blade fan 200 is connected, a plurality of cooling holes for supplying from the multi-blade fan 200 are formed. The air is introduced into the inflow port 22h1 in the outer conductor 22A, and further, at the side of the wall surface of the outer conductor 22A which is connected to the inner conductor 21A and opposite to the inflow port 22h1, a plurality of air for forming the outer conductor 22A are formed. It is discharged to the external outlet port 22h2. By introducing the cooling air through the inflow port 22h1 for the inner conductor 21A whose temperature has risen during the plasma treatment, it is possible to suppress the temperature rise of the inner conductor 21A. Further, by controlling the air volume of the multi-blade fan 200, the temperature of the inner conductor 21A can be set to be slightly constant. If the temperature rise or the temperature change of the inner conductor 21A can be suppressed, the deformation caused by the heat of the inner conductor 21A can be suppressed, and the lower end surface of the inner conductor 21A and the upper surface of the movable conductor plate 21B can be formed. The size of the gap Gp is kept constant, and variation in load impedance can be suppressed.

Modification

In the above embodiment, the sealing member is connected by using a sealing metal. However, the sealing member is not limited thereto, and the sealing member may be directly connected to the inner conductor and the outer conductor by welding, welding, or the like.

In the above embodiment, the sealing member and the discharge preventing member are formed of different materials, but they may be formed of the same material. Further, although the sealing member and the discharge preventing member are set as phases The member may be different, but the sealing member and the discharge preventing member may be integrated to have both a sealing function and a function of the landfill space SP.

In the above-described embodiment, a part of the discharge preventing member is configured by an insulator having fluidity. However, all of the discharge preventing members may be formed of an insulator having fluidity. .

In the above embodiment, the air-cooling mechanism using the multi-blade fan is applied to the apparatus of the second embodiment. However, the air-cooling mechanism can also be applied to the apparatus of the first embodiment.

In the above embodiment, the case where microwaves are used as electromagnetic waves has been described. However, the present invention is not limited thereto, and may be electromagnetic waves of other frequency bands.

Hereinafter, the embodiments of the present invention are described in detail with reference to the accompanying drawings, but the present invention is not limited thereto. As long as there is a general knowledge in the technical field to which the present invention pertains, it is obvious that various modifications and corrections can be made within the scope of the technical idea described in the scope of the patent application, and it should be understood that These are of course within the technical scope of the present invention.

1‧‧‧Plastic processing unit

10‧‧‧Processing chamber

11‧‧‧Confined space

12‧‧‧Internal conductor

13‧‧‧ cover (external conductor)

13h‧‧‧ openings

14‧‧‧Support

16‧‧‧Substrate

20‧‧‧ coaxial tube

21‧‧‧Internal conductor

22‧‧‧External conductor

23‧‧‧ gap

34‧‧‧Dielectric plate

34p‧‧‧ outer peripheral part

36‧‧‧Electrode

50‧‧‧O-ring

60‧‧‧ Sealing members

70, 71‧‧‧ Sealing metal

100‧‧‧Discharge prevention member

100a‧‧‧through hole

100b‧‧‧ outer perimeter

100c‧‧‧ outer perimeter

SP‧‧‧ Space

TM‧‧‧ conductor surface wave

Claims (2)

A plasma processing apparatus characterized by comprising: a processing chamber for dividing a sealed space; and an electrode for forming a plasma, which is disposed in the sealed space; and an inner conductor from the processing chamber The outer portion is extended toward the electrode for forming a plasma by an opening formed at the processing chamber; and the outer conductor surrounds the periphery of the inner conductor, and is partitioned between the outer conductor and the inner conductor a gap, and defining the opening; and a sealing member connected to the inner conductor and the outer conductor, and configured to partition the gap into a space on the atmosphere side and a space in communication with the sealed space, and the insulator And the discharge preventing member is formed by filling a space formed in the sealed space with respect to the sealing member, and is formed of an insulator, and the sealing member is respectively formed by a sealing metal It is connected to the aforementioned inner conductor and outer conductor. A sealing method for a plasma processing apparatus, characterized in that the plasma processing apparatus is provided with: a processing chamber for dividing a sealed space; and an electrode for forming a plasma, which is disposed in the sealed space; An inner conductor formed from the outside of the processing chamber An opening at the processing chamber extends toward the electrode for forming the plasma; and an outer conductor surrounds the periphery of the inner conductor, and a gap is defined between the outer conductor and the inner conductor, and the opening is defined The sealing method of the plasma processing apparatus is characterized in that a sealing member formed of an insulator is connected to the inner conductor and the outer conductor, and the gap is partitioned into a space on the atmosphere side and is connected to the sealed space. The space in which the space is formed in the sealed space with respect to the sealing member is filled with an insulator, and the sealing member is made of the inner conductor and the outer conductor via the sealing metal. connection.